Refactor shared gemspec matcher into a mixin.

lib/rubocop.rb

@@ -83,6 +83,7 @@
 require_relative 'rubocop/cop/mixin/first_element_line_break'
 require_relative 'rubocop/cop/mixin/frozen_string_literal'
 require_relative 'rubocop/cop/mixin/gem_declaration'
+require_relative 'rubocop/cop/mixin/gemspec_help'
 require_relative 'rubocop/cop/mixin/hash_alignment_styles'
 require_relative 'rubocop/cop/mixin/hash_transform_method'
 require_relative 'rubocop/cop/mixin/ignored_pattern'

lib/rubocop/cop/gemspec/date_assignment.rb

@@ -21,21 +21,13 @@ module Gemspec
       #
       class DateAssignment < Base
         include RangeHelp
+        include GemspecHelp
         extend AutoCorrector
 
         MSG = 'Do not use `date =` in gemspec, it is set automatically when the gem is packaged.'
 
-        # @!method gem_specification(node)
-        def_node_matcher :gem_specification, <<~PATTERN
-          (block
-            (send
-              (const
-                (const {cbase nil?} :Gem) :Specification) :new)
-            ...)
-        PATTERN
-
         def on_block(block_node)
-          return unless gem_specification(block_node)
+          return unless gem_specification?(block_node)
 
           block_parameter = block_node.arguments.first.source
 

lib/rubocop/cop/gemspec/duplicated_assignment.rb

@@ -36,20 +36,11 @@ module Gemspec
       #   end
       class DuplicatedAssignment < Base
         include RangeHelp
+        include GemspecHelp
 
         MSG = '`%<assignment>s` method calls already given on line '\
               '%<line_of_first_occurrence>d of the gemspec.'
 
-        # @!method gem_specification(node)
-        def_node_search :gem_specification, <<~PATTERN
-          (block
-            (send
-              (const
-                (const {cbase nil?} :Gem) :Specification) :new)
-            (args
-              (arg $_)) ...)
-        PATTERN
-
         # @!method assignment_method_declarations(node)
         def_node_search :assignment_method_declarations, <<~PATTERN
           (send

lib/rubocop/cop/gemspec/ruby_version_globals_usage.rb

@@ -26,20 +26,13 @@ module Gemspec
       #   end
       #
       class RubyVersionGlobalsUsage < Base
+        include GemspecHelp
+
         MSG = 'Do not use `RUBY_VERSION` in gemspec file.'
 
         # @!method ruby_version?(node)
         def_node_matcher :ruby_version?, '(const {cbase nil?} :RUBY_VERSION)'
 
-        # @!method gem_specification?(node)
-        def_node_search :gem_specification?, <<~PATTERN
-          (block
-            (send
-              (const
-                (const {cbase nil?} :Gem) :Specification) :new)
-            ...)
-        PATTERN
-
         def on_const(node)
           return unless gem_spec_with_ruby_version?(node)
 
@@ -49,7 +42,7 @@ def on_const(node)
         private
 
         def gem_spec_with_ruby_version?(node)
-          gem_specification?(processed_source.ast) && ruby_version?(node)
+          gem_specification(processed_source.ast) && ruby_version?(node)
         end
       end
     end

lib/rubocop/cop/mixin/gemspec_help.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    # Common functionality for checking gem declarations.
+    module GemspecHelp
+      extend NodePattern::Macros
+
+      # @!method gem_specification?(node)
+      def_node_matcher :gem_specification?, <<~PATTERN
+        (block
+          (send
+            (const
+              (const {cbase nil?} :Gem) :Specification) :new)
+          (args
+            (arg $_)) ...)
+      PATTERN
+
+      # @!method gem_specification(node)
+      def_node_search :gem_specification, <<~PATTERN
+        (block
+          (send
+            (const
+              (const {cbase nil?} :Gem) :Specification) :new)
+          (args
+            (arg $_)) ...)
+      PATTERN
+    end
+  end
+end